By JOHN S. TOWNSEND
One of the perennial questions that philosophers ask is: “If a tree falls in the forest and no one is there to hear it, does it make a noise?” This question is applicable to fire or security alarm systems as well as falling trees in a forest. Any alarm system, fire or otherwise is part of a chain of events.
1.) The event triggering the alarm (fire, increase in temperature or pressure, power failure or whatever) occurs,
2.) The alarm signal is activated,
3.) The signal is received by a human operative,
4.) The recipient reacts by notifying the owners and activating the appropriate response,
5.) The response organization initiates the appropriate response action.
Now this is all well and good if step 3 actually happens; the problem is that too many times it does not. Emergencies can and do occur at times when no one is present to hear the alarm, making the human factor the weakest link in the chain.
To this day there are buildings in which sprinkler systems are installed with a large gong mounted on the outside of the structure. This gong is operated by the flow of water through a small Pelton turbine in the supply line. Upon activation of one or more of the sprinkler heads within the building, the flow of water in the supply pipe will cause the gong to sound and, hopefully, alert some passer-by who will then call the police or fire department.
Unfortunately, all too often, this does not work; industrial sites are usually deserted at night. Few people understand what the ringing gong means or what they should do if they hear it ring. Another factor is the functionality of the gong; how long has it been since this device has actually been tested? In many jurisdictions ,testing the gong or other external alerting device is not part of the required protocol for testing sprinkler systems. Another question: who is responsible for running tests on sprinkler or alarm systems?
One of the methods used in colonial days to assure that the community knew that there was a fire in an unattended building was to place barrels of water resting on kegs of gunpowder in the rafters. The powder exploded, showering the contents of the water barrel down on the fire and, coincidently, waking the whole neighborhood. Based on historical accounts, these combination sprinkler-alarm systems actually worked and were often fairly effective, though the exploding gunpowder sometimes caused as much or more damage than the fire.
One of the greatest failings of “off-the-shelf” alarm systems is their inability to record the events that trigger them. If a refrigeration system is shut down by a power failure and then restarts itself when the power is restored, the thermometer may have registered an above limit temperature for a time. However, when the power is restored, the thermometer reverted to an acceptable reading with no one the wiser until spoilage is seen in the contents of the refrigerator. In the case of freezers the readily available solution to this particular problem can be simple and inexpensive.
Back in the “dark ages” when I was an intern, we developed a simple method of determining whether or not defrosting had occurred in the laboratory freezers. We took a small glass bottle with a screw or snap cap (a baby food bottle works fine) added about ¼-inch of water tinted with food color and placed it in the freezer. After the water was frozen, we turned the bottle upside down so that the layer of colored ice was on top. If a thaw occurred, the colored ice melted and dropped to the bottom of the inverted bottle. A quick visual check was all that was needed to confirm that the contents of the freezer were safe. If any of the inverted bottles had water or ice in the lids then we knew that there had been a defrost incident and the stored contents should be tested before use.
The same problems apply to many of the commercially available carbon monoxide alarms used in both residential and small commercial venues. A faulty heating system may trigger the alarm. If the room warms up and the heater turns off, the alarm system resets as the gas dissipates — only to repeat the warning if the temperature falls and the heater starts up again. This is of particular concern in homes or other venues where the occupants sleep and may be overcome before they awaken since carbon monoxide is colorless and odorless in lethal concentrations. It can also have deleterious effects on workers in an office or within an enclosed location in an industrial facility. Often problems of this sort become a case where familiarity breeds contempt. The alarm has been going off, but nothing is seen indicating anything wrong so it is ignored. Then we wonder why when someone is hurt or killed. The alarm was screaming to tell us that something was wrong, but we chose to ignore the notification because we could not see the problem.
Alarm systems are also prone to false alarms, which cause considerable concern among the response and law enforcement agencies responding to trouble calls. These can be engendered by rather unusual occurrences such as a rodent chewing through the wiring of an alarm circuit or the accidental severing of an alarm system wire.
In one instance, streamers were hung from the light fixtures in a church in preparation for Pentecost Sunday. Sometime after midnight the temperature dropped below the thermostat setting. The heating system came on and the streamers, blowing in the circulating air, triggered the motion detectors and an intrusion alarm. By the time the police responded, the heating system had warmed the building and shut down. It was not until the second or third call that someone realized what was happening. The police and the alarm company were not amused. Pentecost streamers have not been hung since.
For an alarm device or system to do its job, it must be designed to insure that some intelligent being gets the signal, realizes that something is wrong and reacts in an appropriate manner. Even in the unlikely event that the problem is due to a malfunction of the alarm system itself, there should be a provision in the design for the system to “fail safe” and display a signal that something is wrong. Though it may not indicate what the nature of the problem specifically is it notifies us that there is indeed a problem and the warning should be taken seriously.
In large establishments such as office buildings, apartment complexes or industrial installations closed circuit surveillance cameras are monitored by an attendant on duty 24/7. If an alarm comes in, the attendant can either see on the screen what caused the alarm or check it out in person. This type of surveillance system works well but it is expensive to operate due to labor costs. Therefore it is not cost effective for small facilities or those situated in remote locations. Such a system is prone to damage in extreme weather or an explosion, thus putting the facility at risk when protection is most needed.
The most common solution to the problems presented is to subscribe for the services of a commercial alarm company such as ADT or Brinks. These companies can, for a fee, design a detection system that will ignore the cause of false alarms and still be sensitive to the risks inherent in the facility.
Sensors can be made for use in remote locations to respond to escapes of specific contaminates such as chlorine in water treatment plants, hydrogen sulfide in oil refineries or ammonia in refrigeration plants. Others can also monitor temperatures and/or pressures in tanks and storage areas alerting operators when either high or low limits are exceeded. Over filling or over pressuring tanks is often remotely monitored, as well as leaks of potentially dangerous substances, before these instances can cause harm to unsuspecting workers. Systems have been designed which will lock the doors to an area when a leak has been detected. It permits entry only to authorized personnel who are in possession of the entry code, and have been trained and are equipped to deal with the incident.
Security system providers also offer 24/7 monitoring of the system, notifying the subscriber and the appropriate response agency in case of an alarm. While these services are generally good, they do have limitations that potential subscribers should understand.
The first question that a potential buyer of alarm or security services should ask is “where is the response center located?” Is it down the street or five hundred miles away? Given today’s technology, it would be prudent to determine if the response center is even in the United States. It is not necessarily a bad thing to have the response center located away from the site under surveillance. In a catastrophic incident such as an explosion or extreme weather event, a remote response center may escape damage and remain operational, but the subscriber needs to know how the system is set up and what protocols are established to deal with such an occurrence.
Second, how will the alarm be transmitted. In most cases, this will be the established telephone system. If this system depends partially on cellular towers, whose towers are involved? Not all cell towers are created equal. Some companies include a small diesel powered standby generator in their tower installations while others employ large battery banks which require recharging from commercial power sources after use. It is important to know how the system is set up and how long service can be expected to be provided from the available standby sources.
Towers equipped with a diesel or propane generator can continue to operate as long as the fuel supply lasts. They are usually equipped with large fuel tanks to minimize the number of trips to refill the tanks. As long as there is fuel in the tanks and oil in the crankcase, the system will continue to operate.
Towers equipped with battery banks will continue to operate only until the batteries are exhausted, after which they must be recharged by commercial power, a process which may require several hours. In a large scale event, the restoration of power for operation and recharge may require several days.
In the case of the conventional “land line” systems, disruption of service often occurs in cases of severe weather or other cataclysmic events such as flooding, earthquake wild land fires or other natural occurrences. Vandalism is also a consideration in some areas. While it is true that many phone lines are now buried, the switching offices, terminal pedestals and other essential appurtenances are not. These are subject to damage and thus put out of service when needed most. Therefore, enquire as to what, if any, back up system is included in the design considered for installation.
It is also prudent to consider whether or not the security system requires a connection to the local power system and what will happen in the event that the local grid fails. A good example is the portable telephones used in homes and offices. If the power goes down, the system ceases to operate even though the telephone company lines are still functioning. For this reason, each domestic or commercial installation should include at least one conventional telephone instrument hard wired into the phone company’s lines.
No security system is perfect but there are good ones available. The prudent prospective purchaser is well advised to know and consider the limitations and shortcomings of any proposed system and plan accordingly for the unexpected.
TESTING AND MAINTENANCE
Another item that should be considered in the design of a security system is testing and maintenance. Once purchased and installed, security systems tend to be forgotten — until something happens and they fail. Then we blame everything — the system, the design, the components, the installer — but ourselves, which is where the blame probably lies. Batteries become exhausted and need to be replaced, cameras become obscured by changes in building configuration or improperly stacked merchandise, detectors expire — particularly in dry climates, wires become corroded or are accidently severed in the course of day to day operations and radio interference from the increasing plethora of wireless devices in use nearby creates radio frequency interference. Any number of things can develop over time that will interfere with the proper functioning of any security system.
Unfortunately, these things do not manifest themselves until something goes wrong and the system fails to respond as expected. Often this “something” is in the form of a power outage.When electricity is restored, the enunciator panel breaks out in a veritable bouquet of notices that batteries are down or detectors are unresponsive. Some of these will resolve themselves after a short time to allow the batteries to recharge, others will require attention from a technician and all of them should be corrected as soon as possible.
The preceding highlights the need for regular scheduled maintenance. After performing all the maintenance checks the system should be thoroughly tested. Normally this testing is performed in accordance with a prearranged schedule and often by the alarm service company. This procedure should show “glitches” in the system. But incidents do not always occur at 10 a.m. on Wednesday; they can happen any time, usually at the most inopportune moment imaginable. Regularly scheduled tests determine the condition of the hardware. Due to the fact that they are expected, they often fail to detect any lapses on the part of the human factor, the third link in the chain.
While it may be a bit disquieting to some of the alarm company personnel, it might be a good idea to walk in at 3 a.m. and pull the manual alarm switch. This will indicate just how awake the alarm company’s response staff is at that hour; it will also test the local response agencies. If the company gets a telephone call from the local emergency dispatch office telling them that they are receiving a fire alarm or if there is a call from the alarm company with the same information, then assume that the systems, both electronic and human, are up and running and the facility is reasonably well protected. If nobody gets a call, then administration needs to have a chat with the alarm company.
One final item that should not be overlooked in the design of a security system is that of local standby power for the system components located in the facility itself. Many “off the shelf” systems include rechargeable batteries that are supposed to power the system in the event of a power failure. These work well, but their capacity is limited. They can be counted on for only a few hours at most.
One way to ensure long term operation of the alarm system is to power it from a larger battery; a large automotive or “deep discharge” golf cart battery is ideal and probably the most cost effective. The battery is hooked up to the alarm system through an inverter and in parallel with an automatic battery charger. The battery “floats” on the line until a power failure occurs. When this happens, the battery continues to power the alarm system until commercial power is restored. At which time the charger replenishes the battery and the system is reset. Meanwhile, it delivers uninterrupted service. Such an arrangement is relatively inexpensive and requires minimal maintenance. Just how long such a system can keep an alarm system operational is dependent on the size and complexity of the system and the capacity of the battery. A simple installation such as those found in homes and small business locations can operate for several days on a good sized truck battery.
The bottom line with regard to security and fire alarm systems is the axiom “take care of the hardware and the hardware will take care of you.” Alarm systems, to be effective, must be taken seriously. They must be inspected, maintained and tested. Blinking lights on the enunciator must be investigated immediately and their cause, whatever it is, remediated. Nothing renders a security system less effective than a signal ignored simply because it has been blinking all day for no apparent reason. There is a reason: a bad battery, a faulty detector or a hungry rodent in search of food. Any number of things can activate a motion detector but, whatever the cause, it needs to be corrected now.
Fire alarm and security systems, sprinkler installations, smoke detectors and carbon monoxide alert systems have saved more lives in the United States than any other protective device. Motion detectors and break-in detectors have prevented more thefts and acts of vandalism or terrorism than we can count.
These systems, like any other piece of business equipment, must be given the care and maintenance that they require to do their job. It is not the cost of the installation that matters. It is what the system saves, both in life and property, by alerting building occupants to just one fire or other hazard.
How much is this peace of mind worth to you and to your business?